The present invention is encompassed in the following fields of the art: aeronautic sector, aerospace sector, high lift devices, automatic flight control systems.
Since the landing of aircraft involves a dangerous situation in addition to needing the existence of suitable installations, inventions and methods intended to assist and facilitate landing thereof in the safest and least expensive manner possible have been carried out throughout the hundred years of practical aviation history.
Besides the most common solution of building suitable airport installations and designing conventional human assisted or automated landing and takeoff systems and improving air traffic control, inventive effort is made in order to obtain systems, methods and devices which allow landing an aircraft in smaller installations or in less equipped installations or, at best, in non-equipped installations.
In that sense, some patent documents of devices and methods intended to solve the aeronautical problem for aiding the landing of aircraft on unprepared or short runways are known.
The patents mentioned and discussed below are those that seem to be the closest to the solution presented in the present invention.                Patent document EP0579508-A1: A device produces an uncontrolled horizontal air current which being added to the air current striking an aircraft approaching a conventional runway, slows the aircraft down, facilitating its landing in a shorter space.        
However the objective sought in the present invention is not to generate an opposing air current which slows down the aircraft but to replace the volume of air in which the aircraft moves with another volume of air, in a smooth and controlled manner, the characteristics of which are under the control of a system which automatically adapts them to the flight conditions of the aircraft by means of coordinating with the flight control system thereof. Therefore, the horizontal air current is not uncontrolled, but is kept coherent and airworthy by means of the corresponding flow control systems, such that an aircraft can maneuver therein maintaining the full aerodynamic control. The term coherent is a physics term applied in aerodynamics and in laser optics meaning that the movement of all the particles is parallel to the general flow direction.                Patent documents U.S. Pat. No. 4,700,912 and US2007/0029442-A1: A device captures the aircraft in an air column supporting the aircraft from below such as on a tray and places it on a certain surface.        
However, the objective sought in the present invention is not to support the aircraft from below by means of injecting an air jet which is capable of keeping the aircraft suspended due to its aerodynamic resistance, but to provide a volume of air in which the aircraft can hover according to the aerodynamic principles for which it has been designed.
Additionally, the present invention has a simpler approach based on cheaper and more portable devices, such that they can easily be moved to non equipped areas in which providing aircraft landing points is desirable. On the other hand, the present invention is easier to carry out and proposes building systems and installations in which the aircraft evolve according to their design principles without being forced to fly against an uncontrolled gale or to ride on a vertical air jet, both situations presenting a high intrinsic hazard.